Geographic Range

Habitat

Pacaranas inhabit the slopes and valleys of rainforests in the Andes mountains. They are thought to be extremely rare, although some scientists speculate that this might be due to a lack of information about the animal's true habitat (White 1992 and Matthews 1971).

Physical Description

Pacaranas are the third largest living rodent with a head and body length ranging from 730-790mm and a tail length of about 190mm (Anderson 1984). Pacaranas have upper parts that are typically dark brown or blackish with two discontinuous white stripes along the back and a few rows of white spots down each side (Burton 1987, Anderson 1984). The ears are relatively short and curved, the upper lip has a deep cleft, and pacaranas have many long, greyish whiskers. The feet are plantigrade and there are four digits on each foot, each with a long and powerful claw (Grzimek 1975 and White 1992).

Reproduction

Little is known about the reproductive characteristics of this species. Pacaranas in captivity have a gestation period of 222-283 days, and the female usually gives birth to no more than two young (Grzimek 1975). Each young weighs about 900g and shows considerable activity and curiosity about its environment within just a few days of birth (White 1992). Weaning period and age of sexual maturity are not known, but the life span of captive pacaranas can be over nine years. It also seems that pacaranas "cry" in the breeding season to attract sexual partners, and males approach females in a bipedal position during courtship (Anderson 1984).

Lifespan/Longevity

Behavior

In captivity, pacaranas are noticeably calm, non-aggressive, and peaceful animals (Matthews 1971 and Grzimek 1975). They appear to be mainly nocturnal and do some climbing, but are predominantly terrestrial. Pacaranas are usually solitary or found in pairs (Parker 1990). There seems to be an elaborate communication system consisting of a combination of foot stamping with fore paws, tooth chattering, whines, songs, and hisses (White 1992 and Anderson 1984). When feeding, they commonly sit on their hind legs and hold the food between the fore paws (Parker 1990). There is still not enough known about their life in the wild. Scientists are not certain whether the long claws of this species are mainly for digging or for climbing because captive pacaranas have not been observed to dig (Grzimek 1975).

Economic Importance for Humans: Positive

Conservation Status

Pacaranas are classified as threatened and possibly on the verge being classified as endangered (Bailie 1996). The classification is mostly due to the animal's rareness. They are probably not significantly affected by deforestation. The most important challenge is to learn more about the pacarana's life history in the wild and its habitat range (Burton 1987 and White 1992).

Contributors

Khoa Huu Nguyen (author), University of Michigan-Ann Arbor.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

folivore

an animal that mainly eats leaves.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

young precocial

young are relatively well-developed when born

References

Anderson, S. and J.K. Jones, Jr. 1984. Orders and Families of REcent Mammals of the World. John Wiley & Sons, New York.

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This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.